Sewing machine attachment



April 1956 J. CONNORS SEWING MACHINE ATTACHMENT Filed June 18, 1953 3 Il 4 4 Av 4 8 V p DJ r Q J a INVENTOR ATTORNEY5 United States PatentOfifice 2,742,871 SEWING MACHINE ATTACHIVIENT Application June 18, 1953,Serial No. 362,467

1 Claim. (Cl. 112-160) This invention relates to a sewing machineattachment and more particularly to an attachment designed to be usedwith the ordinary household sewing machine to perform various kinds ofwork such, for example, as a zig zag attachment, a decorative or blindstitch attachment, or 'a buttonhole attachment among others.

In sewing machine attachments of this character there is provided aframe adapted to be attached to the presser bar of a sewing machine anda lever pivoted to the frame to be oscillated or moved transversely ofthe line of stitching in order to move the material which is beingstitched ous cam track and the follower.

As the parts of these devices are economically made by stamping orsimilar operations, there is sometimes a certain amount of play betweenthe cam follower and the wall of the cam track which is, of course,undesirable in the operation of the finished attachment. Also in someinstances due to continued use of the device a certain amount of wearwill occur either upon the cam follower or upon the parts of the camwhich will result in looseness or play between the parts andunsatisfactory or ineflicient operation.

It is contemplated by the present invention to provide a structure inwhich the cam follower will fit closely at all times between the Wallsof the cam track so that there will be no play or lost motion betweenthese parts,

and the lever will be reciprocated smoothly and efliciently and be giventhe full stroke for which the device is adjusted. While in the presentapplication the invention is shown as applied to a zigzag attachment, itwill be understood that it may be used upon other sewing machineattachments which employ an internal cam track with a follower extendingwithin the track, the follower being mounted upon a part of the devicewhich is to be oscillated or reciprocated in unison with thereciprocations of the needle bar.

One object of the invention is to provide a new and improved sewingmachine attachment wherein an oscillatable or a reciprocable part ismoved by the engagement of a cam follower within an internal cam track.

A still further object of the invention is to provide a sewing machineattachment of the character described wherein the follower engagingwithin an internal cam track is a spring pressed member so arranged thatit will be urged by spring pressure into snug engagement with the wallsor" the cam track.

Still another object of theinvention is to provide a sewing machineattachment of the character described wherein the follower which engageswithin an internal cam track is of conical shape and is spring pressedinto engagement with the walls of the internal cam track whereby it willalways be urged into snug engagement with the walls of the track. I

To these and other ends the invention consists in'the novel features andcombinations of parts to be hereinafter described and claimed.

In the accompanying drawings:

Fig. l is a side elevational view of a sewing machine attachmentembodying my invention;

Fig. 2 is a top plan view thereof;

Fig. 3 is a sectional view on line 33 of Fig- 1-; and

Fig. 4 is an exploded view of the cam follower and associated parts. i

To illustrate a preferred embodiment of my invention I have shown in thedrawings a zigzag sewing machine attachment comprising a U-shaped framehaving a-baseportion 10 and upstanding side walls 11 and 12. Rotatablymounted in the side walls of the frame is a shaft 13 having a cam hub 14thereon. This hub is provided with reduced end portions to formshoulders 15 and 16 thereon, and against each of these shoulders issecured a cam disk, these disks being designated by the numerals 17 and18. These cam disks are of sinuous form, as shown more especially inFigs. 2 and 3, and, when secured to the hub 14 in the manner shown,present between them a sinuous internal cam track 19 (Fig. 2).

Secured to the shaft 13 is a ratchet wheel 20, the teeth tached to theneedle bar of the sewing machine, and when the latter is reciprocated,effecting oscillation of the fork arm 23 which is loosely mounted uponthe shaft 13, the ratchet wheel will be given a step-by-step movementwhich will in turn rotate the cam assembly in a step-bystep movement.

An adapter 24 is secured between the upstanding walls 11 and 12 of theframe, this adapter being securable to the presser bar of the sewingmachine in the usual manner. a

The base 10 of the frame member is provided with a slot 25 whichslidably receives a pivot member 26, and pivoted upon this member is alever 27 carrying a feeding foot 28 at its forward end.

The pin 26 is carried by an adjusting plate 29 and extends upwardlythrough a slot 30 in the lever 27 so that a longitudinal direction aspermitted by the slot 31 to adjust the pivot pin 26.

The plate 29 may be provided at its rear end with a finger piece 33 bywhich it may be adjusted, and at the side edges of the plate are flanges34 and 35 (Fig. 3). The flange 35 is provided with a slot 36 whichreceives a screw 37 threaded into the frame portion 12 so that the screw37 may be tightened and the plate 29 held in any position to which itmay be adjusted in order to adjust the throw of the lever 27.

Secured to the lever 27 adjacent its rear end is a pin between the uppersurface of the lever 27 and the lowersurface of the cam follower 40urges the latter upwardly.

Patented Apr. 24, 1956 From Figs. 1 and 3 of the drawing, it will beapparent that the cam follower 40 extends upwardly within the sinuouscam track betwen the cam plates 17 and 18 and that it is urged upwardlyby the spring 42. As the cam follower 40is in the shape of a frustrum ofa cone or tapered exteriorly, it will be forced upwardly by the springuntil its periphery makes snug engagement with the cam plates Hand 18.If there is any imperfection in the manufacture of the device or wear inthe parts due to continued operation, any looseness or play between thecam follower and the cam plates 17 and 18 will be taken up by the upwardmovement of the cam follower under pressure of the spring 42.

Moreover, the fit between these parts will always be controlled bypressure of the spring 42 and, even if the width of the cam track shouldbe uneven or greater at one point than another, the floating action ofthe cam follower wil compensate for any such unevenness and will providethe proper snug engagement between these parts.

While I have shown and described a preferred embodiment of my invention,it will be understood that it is not to be limited to all of the detailsshown, but is capable of modification and variation within the spirit ofthe invention and within the scope of the claim.

What I claim is:

A sewing machine attachment comprising a frame, a

lever pivoted on the frame, means for oscillating said lever about thepivotal axis thereof comprising a rotatable cam member having aninternal cam track in the form of a sinuous channel having substantiallyparallel side walls, a pin having one end thereof fixed to said leverand having an outer free end extending toward said cam track, a camfollower in the form of a truncated cone having an axial bore formedtherein snugly receiving said free end of the pin, said cam followerbeing axially slidable on said free end of the pin and being free torevolve thereon, and said cam follower extending into said channel andterminating short of the bottom of the latter, and a compression springintermediate the lever and said cam follower and constantly urging thelater toward and against the side walls of the channel, wherebyundesirable play of the cam follower is effectively inhibited.

References (Iited in the file of this patent UNITED STATES PATENTS2,525,922 Mandl Oct. 17, 1950 2,554,971 Adler May 29, 1951 2,592,653Burgess Apr. 15, 1952 2,655,119 Enos Oct. 13, 1953 FOREIGN PATENTS289,675 Great Britain May 3, 1928

